Sound source localization refers to a listener's ability to identify the location or origin of a detected sound in direction and distance. The human auditory system uses several cues for sound source localization, including time and sound-level differences between two ears, timing analysis, correlation analysis, and pattern matching.
Traditionally, non-iterative techniques for localizing a source employ localization formulas that are derived from linear least-squares “equation error” minimization, while others are based on geometrical relations between the sensors and the source. Signals propagating from a source arrive at the sensors at times dependent on the source-sensor geometry and characteristics of the transmission medium. Measurable differences in the arrival times of source signals among the sensors are used to infer the location of the source. In a constant velocity medium, the time differences of arrival (TDOA) are proportional to differences in source-sensor range (RD). However, finding the source location from the RD measurements is typically a cumbersome and expensive computation.